1. Field of Invention
The present invention relates to dry powder delivery system, and more particular to an internal dry powder delivery system and method thereof for delivering dry powder to reach internal operation site, especially during a minimally invasive surgery or other similar internal application for beings such as humans or animals.
2. Description of Related Arts
Generally, medications are in liquid form, capsule form, pill form, and powder form. The common difficulty for physicians is how to directly apply powdered medication to the internal tissue/organ site of a human or an animal such as human gastro-intestine.
Traditionally, the only application of powdered medications is to enclose the powder in a capsule made of a material that will not immediately dissolve or to compress the powder into the pill form. When the capsule or pill is consumed into the patient's stomach and intestine, the enclosure skin of the capsule will dissolve and the powder particles will be exposed and absorbed.
Conventionally, powder form medications can be applied by topical application during open surgery. It may normally be ingested as tablets or powder capsules. Tablets and powder capsules' strengths are often diluted by gastric and intestinal juice and could not offer precise delivery and dosage control to the target wound site. In turn, physicians can not accurately control the amount of medication reaching the designated site on the gastrointestinal tract. Therefore, it cannot be used when physicians want to directly control the dosage and dryness status of the powder to apply the target wound sites of human gastro-intestine before contact with liquid in the digestive system.
The minimal invasive procedure via endoscope has been widely used for diagnosis and surgery. When using endoscope during inspection and surgery, physicians often need to apply medications to an internal tissue site. Via endoscope, physicians can inspect the internal organ/tissue and conduct surgical procedures inside of the human body. In general, endoscopes consist of gastro-intestinal endoscope, laparoscope, thoracoscope, hysteroscope, cytoscope, laryngoscope, and nasopharyngoscope etc. Besides for medical use, endoscopes can also be used to inspect mechanical or electrical problems in the industries such as automobile maintenance, mechanical setups, petroleum engineering, electrical facilities, aviator equipments, coal-gas passages, architectures, water pipe systems etc.
For example, gastro and intestinal endoscopes have a standard total length about 1300 mm to 1400 mm depend on the application purpose. Besides the imaging system, the internal components include a narrow working channel, similar to that of an irrigation channel or a biopsy clamp, allowing physicians to conduct minimally invasive surgeries. Currently, the cannula of the gastro and intestinal endoscopes most common used by physicians for biopsy, have a diameter of less than 2.8 mm and 3.2 mm respectively to enable physicians to insert catheters or devices to conduct examination, electrical incision, suture, applying medication and hemostasis, etc.
Physicians often use gastro and intestinal endoscopes during treatment and minimally invasive surgery to examine an internal site or to inject liquid medications. The long and narrow characteristics of the working channel often cause occlusion when injecting medications which could present certain limitations. In current clinical settings, endoscope's irrigation or working channel could only delivery liquid form medications (soluble/insoluble solutions and gel), restricting any powder and particle form medications that could easily lose its effectiveness when it comes in contact with water prior to blood. In addition, through the use of endoscopes physicians could often examine gastritis lesions including tumors or ulcers and thereby provide the appropriate topical medication directly to the site. Due to the length and the narrowness of most gastro and intestinal endoscopes, particles often could not overcome the resistance presented between air pressure and the inner lining of the tube which could lead to tip occlusion. Also, gastro and intestinal juice/mucus could easily enter the working channel causing obstruction. The most common problems associated with delivering dry powder medication through the working channel of an endoscopic cannula include that dry powder particles often occlude because of resistance in the long and narrow cannula through the working channel of endoscope and excess liquid and pressurized air mixed with dry particles could cause occlusion at the tip of the delivery catheter. These common problems minimize physicians' ability to deliver powered medications directly and precisely to the tissue/organ site of the human gastro-intestine via endoscope.
Recently, natural orifice transluminal endoscopic surgery was developed for minimally invasive surgical technique. The endoscope is inserted through natural orifices (such as mouth, anus and vagina) allowing for intra-abdominal diagnostic and therapeutic procedures without the need for abdominal incisions. Moreover, the endoscope can also be inserted into pre-existing orifices to access other body cavities (i.e. thoracic cavity and pelvic cavity). Hence a technique that utilizes the working channel of the endoscope as a vehicle to directly deliver medication to the internal target tissue/organ has great clinical implications in medicine.
The current invention specifically addresses these issues and provides physicians a new alternative to delivery particles/powder format medications directly to an internal site of gastrointestinal tract and body cavities via endoscope during minimally invasive surgeries for both diagnostic and therapeutic purposes.